The Primate Core provides a highly specialized, AAALAC approved resource, with the expertise to provide remote infusion and sampling capabilities for researchers using the non-human primate model for reproductive studies. In addition to providing basic housing it has facilities for surgery, laboratory space and secretarial services. It will provide services to three projects of the current proposal (51% total time) and serve four other projects directly relevant to aims of the current proposal. In total, these services are projected to account for 88% of the work load in the first year. The unit is staffed by very experienced personnel and can provide a reliable, virtually unique, resource for the complex animal access methods used extensively in the proposed projects. Dr. Tony Plant has acted as Director for the past two years. It is proposed that he will continue in that capacity. The allocation of Core resources is controlled by the Primate Core Committee, chaired by Dr. Zeleznik. Veterinary care is provided by the Division of Laboratory Animal Resources (DLAR), headed by Dr. Ed Cline. DLAR employs four veterinarians and one of them visits the Primate Facility at least daily. In the present proposal there has been a change in the accounting methods, in the future, research projects will be billed individually for per diem and animal costs, whereas previously, those costs were part of the Core budget.